Create Audit System in SQL Server 2008

I have a large SQL Server 2008 Database which is used by Web application, Desktop Application, Other processes and by direct users using SQL Management Studio. I am looking to create a Audit System to capture data inserts, updates and deleted done using any of the above processes. Please state any experience you have in this area and how you will be implementing whether you will be using Context_INFO or Trigger or create a wrapper or use CLR etc This bid is to create a prototype in 2 to 3 tables in the database and change the processes to see how efficiently Audit is getting captured. If the prototype is successful we will go to full implementation. Thanks for bidding.